1. Field of the Invention
The present invention relates to a robot programming apparatus for creating a robot program to be taught to a robot used to process a workpiece.
2. Description of the Related Art
There is known a structure for a robot system used to process a workpiece, which is provided with an image pickup device for capturing an image of a portion of the workpiece that is to be processed. Since workpieces vary in shape depending on individual ones, a workpiece processing program is corrected by capturing an image of a portion to be processed using an image pickup device and processing the obtained image. JP-A-06-328385, JP-A-2002-086376, JP-A-2003-191194, JP-A-2007-160486, and JP-A-2009-303013 disclose various techniques for determining a position and a posture of a visual sensor to detect a target object.
JP-A-06-328385 discloses a posture control method for controlling a posture of a visual sensor so that a position of a target portion to be welded can be detected. In this technique, the posture of the visual sensor is controlled in each sampling cycle so that a detection target is always arranged in the center of a visual field of the visual sensor even when a tool moves.
JP-A-2002-086376 discloses a guiding method for guiding a visual sensor attached to a tip of a hand of a manipulator to a target object to be detected. In this technique, a position for guiding the sensor is determined based on an approximate position of the target object and a distance between a predetermined position for guiding the sensor and the target object.
JP-A-2003-191194 discloses correcting the position for guiding a visual sensor in the technique disclosed in JP-A-2002-086376, according to a designated offset in order to avoid an obstacle positioned around the position for guiding the visual sensor.
JP-A-2007-160486 discloses an off-line programming apparatus configured to automatically create a measurement program for capturing an image of a reference point of a workpiece using a visual sensor.
JP-A-2009-303013 discloses an image pickup direction determination program for determining an image capturing direction of an image pickup apparatus configured to capture an image of a surrounding target object in order to estimate a present position of a movable robot configured to move to a predetermined target point.
In the conventional techniques, it is necessary to determine a position of the image pickup device used to capture an image of the target portion to be captured. However, determination of the position of the image pickup device usually requires a lot of time and labor, thus reducing work efficiency. There has thus been a need to determine, efficiently in a short period of time, the position of an image pickup device when the image pickup device captures an image of a target portion.